32K SPI Bus Serial EEPROM · 32K SPI Bus Serial EEPROM *25XX320 is used in this document as a generic part number for the 25AA320/25LC320/25C320 devices. Not recommended for new designs
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
25AA320/25LC320/25C32032K SPI Bus Serial EEPROM
Not recommended for new designs –Please use 25AA320A or 25LC320A.
• 8-Pin PDIP, SOIC and TSSOP Packages• 14-Lead TSSOP Package• Temperature Ranges Supported:
Description:The Microchip Technology Inc. 25AA320/25LC320/25C320 (25XX320*) are 32 Kbit serial ElectricallyErasable PROMs. The memory is accessed via asimple Serial Peripheral Interface (SPI) compatibleserial bus. The bus signals required are a clock input(SCK) plus separate data in (SI) and data out (SO)lines. Access to the device is controlled through a ChipSelect (CS) input.
Communication to the device can be paused via thehold pin (HOLD). While the device is paused,transitions on its inputs will be ignored, with theexception of Chip Select, allowing the host to servicehigher priority interrupts.
All inputs and outputs w.r.t. VSS ........................................................................................................ -0.6V to VCC + 1.0V
Storage temperature .................................................................................................................................-65°C to 150°C
Ambient temperature under bias ...............................................................................................................-40°C to 125°C
ESD protection on all pins ..........................................................................................................................................4 kV
TABLE 1-1: DC CHARACTERISTICS
† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to thedevice. This is a stress rating only and functional operation of the device at those or any other conditions above thoseindicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for anextended period of time may affect device reliability.
DC CHARACTERISTICS Industrial (I): TA = -40°C to +85°C VCC = 1.8V to 5.5VAutomotive (E):TA = -40°C to +125°C VCC = 2.5V to 5.5V
Param.No. Sym. Characteristics Min. Max. Units Conditions
D1 VIH1 High-level input voltage
2.0 VCC+1 V VCC ≥ 2.7V (Note)D2 VIH2 0.7 VCC VCC+1 V VCC< 2.7V (Note)D3 VIL1 Low-level input
AC CHARACTERISTICS Industrial (I): TA = -40°C to +85°C VCC = 1.8V to 5.5VAutomotive (E): TA = -40°C to +125°C VCC = 2.5V to 5.5V
Param.No. Sym. Characteristic Min. Max. Units Conditions
1 FCLK Clock Frequency ———
321
MHzMHzMHz
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
2 TCSS CS Setup Time 100250500
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
3 TCSH CS Hold Time 150250475
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
4 TCSD CS Disable Time 500 — ns —5 TSU Data Setup Time 30
5050
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
6 THD Data Hold Time 50100100
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
7 TR CLK Rise Time — 2 μs (Note 1)8 TF CLK Fall Time — 2 μs (Note 1)9 THI Clock High Time 150
230475
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
10 TLO Clock Low Time 150230475
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
11 TCLD Clock Delay Time 50 — ns —12 TCLE Clock Enable Time 50 — ns —13 TV Output Valid from
Clock Low———
150230—
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
14 THO Output Hold Time 0 — ns (Note 1)15 TDIS Output Disable Time —
——
200250—
nsnsns
VCC = 4.5V to 5.5V (Note 1)VCC = 2.5V to 5.5V (Note 1)VCC = 1.8V to 5.5V
16 THS HOLD Setup Time 100100200
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
17 THH HOLD Hold Time 100100200
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
18 THZ HOLD Low to Output High-Z
100150200
———
nsnsns
VCC = 4.5V to 5.5V (Note 1)VCC = 2.5V to 5.5V (Note 1)VCC = 1.8V to 5.5V
19 THV HOLD High to Output Valid
100150200
———
nsnsns
VCC = 4.5V to 5.5VVCC = 2.5V to 5.5VVCC = 1.8V to 5.5V
20 TWC Internal Write Cycle Time
— 5 ms —
21 — Endurance 1M — E/W Cycles
(Note 2)
Note 1: This parameter is periodically sampled and not 100% tested.2: This parameter is not tested but established by characterization. For endurance estimates in a specific application,
please consult the Total Endurance™ Model which can be obtained from Microchip’s web site at: www.microchip.com.
2.0 PIN DESCRIPTIONSThe descriptions of the pins are listed in Table 2-1.
TABLE 2-1: PIN FUNCTION TABLE
2.1 Chip Select (CS)A low level on this pin selects the device. A high leveldeselects the device and forces it into Standby mode.However, a programming cycle which is alreadyinitiated or in progress will be completed, regardless ofthe CS input signal. If CS is brought high during aprogram cycle, the device will go into Standby mode assoon as the programming cycle is complete. When thedevice is deselected, SO goes to the high-impedancestate, allowing multiple parts to share the same SPIbus. A low-to-high transition on CS after a valid writesequence initiates an internal write cycle. After power-up, a low level on CS is required prior to any sequencebeing initiated.
2.2 Serial Output (SO)The SO pin is used to transfer data out of the 25XX320.During a read cycle, data is shifted out on this pin afterthe falling edge of the serial clock.
2.3 Write-Protect (WP)This pin is used in conjunction with the WPEN bit in theSTATUS register to prohibit writes to the nonvolatilebits in the STATUS register. When WP is low andWPEN is high, writing to the nonvolatile bits in the STA-TUS register is disabled. All other operations functionnormally. When WP is high, all functions, includingwrites to the nonvolatile bits in the STATUS registeroperate normally. If the WPEN bit is set, WP low duringa STATUS register write sequence will disable writingto the STATUS register. If an internal write cycle hasalready begun, WP going low will have no effect on thewrite.
The WP pin function is blocked when the WPEN bit inthe STATUS register is low. This allows the user toinstall the 25XX320 in a system with WP pin groundedand still be able to write to the STATUS register. TheWP pin functions will be enabled when the WPEN bit isset high.
2.4 Serial Input (SI)The SI pin is used to transfer data into the device. Itreceives instructions, addresses, and data. Data islatched on the rising edge of the serial clock.
2.5 Serial Clock (SCK)The SCK is used to synchronize the communicationbetween a master and the 25XX320. Instructions,addresses, or data present on the SI pin are latched onthe rising edge of the clock input, while data on the SOpin is updated after the falling edge of the clock input.
2.6 Hold (HOLD)The HOLD pin is used to suspend transmission to the25XX320 while in the middle of a serial sequence with-out having to re-transmit the entire sequence again. Itmust be held high any time this function is not beingused. Once the device is selected and a serialsequence is underway, the HOLD pin may be pulledlow to pause further serial communication withoutresetting the serial sequence. The HOLD pin must bebrought low while SCK is low, otherwise the HOLDfunction will not be invoked until the next SCK high-to-low transition. The 25XX320 must remain selected dur-ing this sequence. The SI, SCK, and SO pins are in ahigh-impedance state during the time the device ispaused and transitions on these pins will be ignored. Toresume serial communication, HOLD must be broughthigh while the SCK pin is low, otherwise serialcommunication will not resume. Lowering the HOLDline at any time will tri-state the SO line.
Name PDIP SOIC 8-pinTSSOP
14-leadTSSOP Description
CS 1 1 3 1 Chip Select InputSO 2 2 4 2 Serial Data OutputNC — — — 3,4,5 Not Connected
WP 3 3 5 6 Write-Protect PinVss 4 4 6 7 GroundSI 5 5 7 8 Serial Data Input
SCK 6 6 8 9 Serial Clock InputNC — — — 10,11,12 Not Connected
HOLD 7 7 1 13 Hold InputVcc 8 8 2 14 Supply Voltage
3.1 Principles Of OperationThe 25XX320 are 4096 byte Serial EEPROMsdesigned to interface directly with the Serial PeripheralInterface (SPI) port of many of today’s popularmicrocontroller families, including Microchip’sPIC16C6X/7X microcontrollers. It may also interfacewith microcontrollers that do not have a built-in SPI portby using discrete I/O lines programmed properly withthe software.
The 25XX320 contains an 8-bit instruction register. Thedevice is accessed via the SI pin, with data beingclocked in on the rising edge of SCK. The CS pin mustbe low and the HOLD pin must be high for the entireoperation.
Table 3-1 contains a list of the possible instructionbytes and format for device operation. All instructions,addresses and data are transferred MSB first, LSB last.
Data is sampled on the first rising edge of SCK after CSgoes low. If the clock line is shared with otherperipheral devices on the SPI bus, the user can assertthe HOLD input and place the 25XX320 in ‘HOLD’mode. After releasing the HOLD pin, operation willresume from the point when the HOLD was asserted.
3.2 Read SequenceThe device is selected by pulling CS low. The 8-bitREAD instruction is transmitted to the 25XX320 fol-lowed by the 16-bit address, with the four MSBs of theaddress being “don’t care” bits. After the correct READinstruction and address are sent, the data stored in thememory at the selected address is shifted out on theSO pin. The data stored in the memory at the nextaddress can be read sequentially by continuing to pro-vide clock pulses. The internal Address Pointer is auto-matically incremented to the next higher address aftereach byte of data is shifted out. When the highestaddress is reached (0FFFh), the address counter rollsover to address 0000h allowing the read cycle to becontinued indefinitely. The read operation is terminatedby raising the CS pin (Figure 3-1).
3.3 Write SequencePrior to any attempt to write data to the 25XX320, thewrite enable latch must be set by issuing the WRENinstruction (Figure 3-4). This is done by setting CS lowand then clocking out the proper instruction into the25XX320. After all eight bits of the instruction aretransmitted, the CS must be brought high to set thewrite enable latch. If the write operation is initiatedimmediately after the WREN instruction without CSbeing brought high, the data will not be written to thearray because the write enable latch will not have beenproperly set.
Once the write enable latch is set, the user mayproceed by setting the CS low, issuing a WRITEinstruction, followed by the 16-bit address, with the fourMSBs of the address being “don’t care” bits, and thenthe data to be written. Up to 32 bytes of data can besent to the 25XX320 before a write cycle is necessary.The only restriction is that all of the bytes must residein the same page. A page address begins with xxxxxxxx xxx0 0000 and ends with xxxx xxxx xxx11111. If the internal address counter reaches xxxxxxxx xxx1 1111 and the clock continues, the counterwill roll back to the first address of the page and over-write any data in the page that may have been written.
For the data to be actually written to the array, the CSmust be brought high after the Least Significant bit (D0)of the nth data byte has been clocked in. If CS isbrought high at any other time, the write operation willnot be completed. Refer to Figure 3-2 and Figure 3-3for more detailed illustrations on the byte writesequence and the page write sequence, respectively.While the write is in progress, the STATUS register maybe read to check the status of the WPEN, WIP, WEL,BP1 and BP0 bits (Figure 3-6). A read attempt of amemory array location will not be possible during awrite cycle. When the write cycle is completed, thewrite enable latch is reset.
TABLE 3-1: INSTRUCTION SET
Instruction Name Instruction Format Description
READ 0000 0011 Read data from memory array beginning at selected address
WRITE 0000 0010 Write data to memory array beginning at selected address
Disable (WRDI)The 25XX320 contains a write enable latch. SeeTable 3-3 for the Write-Protect Functionality Matrix.This latch must be set before any write operation will becompleted internally. The WREN instruction will set thelatch, and the WRDI will reset the latch.
The following is a list of conditions under which thewrite enable latch will be reset:
(RDSR)The Read Status Register instruction (RDSR) providesaccess to the STATUS register. The STATUS registermay be read at any time, even during a write cycle. TheSTATUS register is formatted as follows:
The Write-In-Process (WIP) bit indicates whether the25XX320 is busy with a write operation. When set to a‘1’, a write is in progress; when set to a ‘0’, no write isin progress. This bit is read-only.
The Write Enable Latch (WEL) bit indicates the statusof the write enable latch. When set to a ‘1’, the latchallows writes to the array, when set to a ‘0’, the latchprohibits writes to the array. The state of this bit canalways be updated via the WREN or WRDI commandsregardless of the state of write protection on the STA-TUS register. This bit is read-only.
The Block Protection (BP0 and BP1) bits indicatewhich blocks are currently write-protected. These bitsare set by the user issuing the WRSR instruction. Thesebits are nonvolatile.
(WRSR)The Write Status Register instruction (WRSR) allows theuser to select one of four levels of protection for thearray by writing to the appropriate bits in the STATUSregister. The array is divided up into four segments.The user has the ability to write-protect none, one, two,or all four of the segments of the array. The partitioningis controlled as shown in Table 3-2.
The Write-Protect Enable (WPEN) bit is a nonvolatilebit that is available as an enable bit for the WP pin. TheWrite-Protect (WP) pin and the Write-Protect Enable(WPEN) bit in the STATUS register control the pro-grammable hardware write-protect feature. Hardwarewrite protection is enabled when WP pin is low and theWPEN bit is high. Hardware write protection is disabledwhen either the WP pin is high or the WPEN bit is low.
When the chip is hardware write-protected, only writesto nonvolatile bits in the STATUS register are disabled.See Table 3-3 for a matrix of functionality on the WPENbit.
* Standard marking consists of Microchip part number, year code, week code, and traceability code. Fordevice markings beyond this, certain price adders apply. Please check with your Microchip Sales Office.For QTP devices, any special marking adders are included in QTP price.
Legend: XX...X Customer-specific informationY Year code (last digit of calendar year)YY Year code (last 2 digits of calendar year)WW Week code (week of January 1 is week ‘01’)NNN Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn)* This package is Pb-free. The Pb-free JEDEC designator ( )
can be found on the outer packaging for this package.
Note: In the event the full Microchip part number cannot be marked on one line, it willbe carried over to the next line, thus limiting the number of availablecharacters for customer-specific information.
THE MICROCHIP WEB SITEMicrochip provides online support via our WWW site atwww.microchip.com. This web site is used as a meansto make files and information easily available tocustomers. Accessible by using your favorite Internetbrowser, the web site contains the followinginformation:
• Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s guides and hardware support documents, latest software releases and archived software
• General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing
• Business of Microchip – Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives
CUSTOMER CHANGE NOTIFICATION SERVICEMicrochip’s customer notification service helps keepcustomers current on Microchip products. Subscriberswill receive e-mail notification whenever there arechanges, updates, revisions or errata related to aspecified product family or development tool of interest.
To register, access the Microchip web site atwww.microchip.com, click on Customer ChangeNotification and follow the registration instructions.
CUSTOMER SUPPORTUsers of Microchip products can receive assistancethrough several channels:
• Distributor or Representative• Local Sales Office• Field Application Engineer (FAE)• Technical Support• Development Systems Information Line
Customers should contact their distributor,representative or field application engineer (FAE) forsupport. Local sales offices are also available to helpcustomers. A listing of sales offices and locations isincluded in the back of this document.
Technical support is available through the web siteat: http://support.microchip.com
READER RESPONSEIt is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentationcan better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.
Please list the following information, and use this outline to provide us with your comments about this document.
To: Technical Publications Manager
RE: Reader ResponseTotal Pages Sent ________
From: Name
CompanyAddressCity / State / ZIP / Country
Telephone: (_______) _________ - _________
Application (optional):
Would you like a reply? Y N
Device: Literature Number:
Questions:
FAX: (______) _________ - _________
DS21227F25AA320/25LC320/25C320
1. What are the best features of this document?
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this document easy to follow? If not, why?
4. What additions to the document do you think would enhance the structure and subject?
5. What deletions from the document could be made without affecting the overall usefulness?
6. Is there any incorrect or misleading information (what and where)?
Note the following details of the code protection feature on Microchip devices:• Microchip products meet the specification contained in their particular Microchip Data Sheet.
• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions.
• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
• Microchip is willing to work with the customer who is concerned about the integrity of their code.
• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of ourproducts. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such actsallow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding deviceapplications and the like is provided only for your convenienceand may be superseded by updates. It is your responsibility toensure that your application meets with your specifications.MICROCHIP MAKES NO REPRESENTATIONS ORWARRANTIES OF ANY KIND WHETHER EXPRESS ORIMPLIED, WRITTEN OR ORAL, STATUTORY OROTHERWISE, RELATED TO THE INFORMATION,INCLUDING BUT NOT LIMITED TO ITS CONDITION,QUALITY, PERFORMANCE, MERCHANTABILITY ORFITNESS FOR PURPOSE. Microchip disclaims all liabilityarising from this information and its use. Use of Microchipdevices in life support and/or safety applications is entirely atthe buyer’s risk, and the buyer agrees to defend, indemnify andhold harmless Microchip from any and all damages, claims,suits, or expenses resulting from such use. No licenses areconveyed, implicitly or otherwise, under any Microchipintellectual property rights.
The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
FilterLab, Linear Active Thermistor, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, mTouch, PICkit, PICDEM, PICDEM.net, PICtail, PIC32 logo, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.
All other trademarks mentioned herein are property of their respective companies.
Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.